Can someone help? I cant create a custom resolution.

So I was looking into custom resolutions for fortnite and one of the steps was to make custom rez using your AMD settings, so I went in there and I didn't see the "Create a custom resolution." I have been looking everywhere and trying everything to fix this but nothing seems to work. Can someone help? Thank you!

** Windows 7 and Windows 8.1 must be fully updated before attempting to install any AMD driver. All 'critical', 'recommended', and 'optional' (no language packs,etc) updates as well as any Service Packs (SP) must be installed before any attempt to install graphics drivers. If you do not get this message .... keep installing until you do: